There seems to be no mention of how the AM or FM tunes.
Does it tune continuously, which would allow side tuning to avoid an iboc mess on sideband of an AM signal?
Is the IF bandwidth on the AM muddy or wideband of at least 20 khx, which allows hearing the 10kc whistle?
IF it just stops on sprecific steps, it could still be OK if the steps sare small enough.
If it only stops on 10 khz spacing on AM, it's another radioemulator as opposed to a radio.
A gritty noise may mean some kind of weird superhet stage with square wave mixer instead of sine wave mixer.